We are offering hosted VoIP. The Asterisk servers are running in our data center and customers connect their Aastra phones remotely to it. However, I have one customers connected to his own PBX and he is having connection issues. The phones often lose their connection to the server (No service) and sometimes their ongoing call is simply cut off and all phones lose connection to the server. I have checked the logs but there doesn't seem to be anything unusual, so I have started to wonder if their hardware setup might be the cause.
Here is how they are setup :
Their Internet connection arrives at their office from a modem, which is then connected to their ISP router to provide their static IP. This then goes in their Netgear router for a DHCP server. Then, this is connected to their 3com Switch to provide all their office.
Their phones are connected to the switch and their computer are connected to their phones. I was wondering if the setup, or the switch/router could be the problem. I have ordered a new switch and a new router, as the switch is pretty old.
I would like to know if you guys have any idea that could help me find the source of this problem. I can provide more information if needed.